Prior to the present invention the running of a casing hanger and annulus seal required separate trips, some rotation, external hydraulic lines or special retrieval tool. The A. G. Ahlstone U.S. Pat. No. 3,924,678 discloses the running of a casing hanger and packing or annulus seal in a single trip but uses rotational release of the running tool.
The J. A. Haber U.S. Pat. No. 3,543,847 discloses a casing hanger apparatus which can be run, cemented and then packed and locked without rotation of the string. Various darts are used to allow string pressure or annulus pressure to control operations. The packing is set by weight and pressure. Once set, it requires a special retrieval tool to retrieve the packing and lock dogs.
The A. G. Ahlstone U.S. Pat. No. 3,468,559 discloses a hydraulically actuated casing hanger having a seat protector which is run with the casing hanger. Packing is set by pressure and torque can be used to apply further setting pressure.
Other patents such as U.S. Pat. Nos. 3,871,449, 3,897,823 and 3,903,965 disclose hangers and hanger packers which are released by rotation; U.S. Pat. Nos. 3,924,679 and 3,933,202 disclose running hangers and packing and the packing set and then locked by rotation; and Pat. Nos. 3,913,670, 3,924,678 and 4,067,062 disclose running hangers and packing and setting the packers by weight or hydraulics and releasable by hydraulics.